This invention relates to novel N-benzenesulfonyl L-proline compounds. These compounds are useful as antagonists of bradykinin, and are thus useful in the treatment of inflammation, asthma, allergic rhinitis, pain or the like in mammalian, especially humans. The present invention also relates to a pharmaceutical composition comprising the above compounds.
Bradykinin (xe2x80x9cBKxe2x80x9d) is generated under normal conditions in mammalia by the action of various plasma enzymes such as kallikrein on high molecular weight kininogens. It is widely distributed in mammals, and relates its two receptor subtypes, B1 and B2. The actions of BK at the B2 receptor include mainly contraction of arterial and venous preparations, although it can cause relaxation of peripheral resistance vessels as well.
Many of the more important functions of BK, such as increases in vascular permeability, pain, and vasodilatation, however, are mediated by the B2 receptor. These effects at the B2 receptor are believed to be responsible for BK""s role in numerous diseases, such as inflammation, cardiovascular disease, pain, and the common cold. Hence antagonists at the B2 receptor should find considerable therapeutic applications. Most of the efforts in this area thus far have been directed at peptidic analogues of the BK structure, some of which have been studied as analgesics and antiinflammatory agents.
Numerous N-benzenesulfonyl L-proline compounds as a B2 antagonist have been synthesized, and disclosed in a number of patent publications such as international publication Nos. WO 97/41104, WO 96/13485, WO 99/00387, WO 98/24783, WO 98/03503, WO 97/24349, WO 97/07115 and WO 96/40639.
International Publication Number WO 98/24783, WO 98/03503, WO 97/24349, WO 97/07115 disclose a variety of N-benzenesulfonyl L-proline compounds as antagonists of bradykinin.
It would be desirable if there were provided a non-peptide antagonist of the B2 receptor, having an improved B2 antagonistic activity and a good metabolic stability against human liver microsomes.
The present invention provides a compound of the following formula: 
or the pharmaceutically acceptable salts thereof wherein
X1 and X2 are independently halo or C1-4 alkyl;
R1 and R2 are independently hydrogen or C1-4 alkyl;
R3 and R4 are independently hydrogen or halo; and
R5 is
(a) xe2x80x94C3-9 diazacycloalkyl optionally substituted with C5-11 azabicycloalkyl;
(b) xe2x80x94C3-9 azacycloalkyl-NHxe2x80x94(C5-11, azabicycloalkyl optionally substituted with C1-4 alkyl);
(c) xe2x80x94NHxe2x80x94C1-3 alkyl-C(O)xe2x80x94C5-11 diazabicycloalkyl;
(d) xe2x80x94NHxe2x80x94C1-3 alkyl-C(O)xe2x80x94NHxe2x80x94C5-11 azabicycloalkyl, the C5-11 azabicycloalkyl being optionally substituted with C1-4 alkyl;
(e) xe2x80x94C3-9 azacycloalkyl optionally substituted with C3-9 azacycloalkyl; or
(f) xe2x80x94NHxe2x80x94C1-5 alkyl-NHxe2x80x94C(O)xe2x80x94C4-9 cycloalkyl-NH2.
The N-benzenesulfonyl L-proline compounds of this invention have an antagonistic action towards bradykinin and are thus useful in therapeutics, particularly for the treatment of inflammation, rheumatoid arthritis, cystitis, post-traumatic and post ischemic cerebral edema, liver cirrhosis, Alzheimer""s disease, cardiovascular disease, pain, common cold, allergies, asthma, pancreatitis, burns, virus infection, head injury, multiple trauma, rhinitis, hepatorenal failure, diabetes, metastasis, pancreatitis, neovascularization, corneal haze, glaucoma, ocular pain, ocular hypertension or the like in mammalian, especially humans.
The N-benzenesulfonyl L-proline compounds of this invention have an antagonistic action towards bradykinin and are thus useful in therapeutics, particularly for the treatment of Amyotrophic lateral sclerosis, Huntington""s disease, Parkinson""s disease, multiple sclerosis, stroke, head trauma, post-surgical brain edema, brain edema (general), cytotoxic brain edema (such as that associated with brain tumors, stroke, head trauma, etc.), brain edema associated with metabolic diseases (renal failure, pediatric metabolic diseases, etc.), rheumatoid arthritis, osteoarthritis, migraine, neuropathic pain, pruritis, brain tumor, pseudotumor cerebri, glaucoma, hydrocephalus, spinal cord trauma, spinal cord edema, neurodegenerative diseases, respiratory diseases, diuresis, natriuresis calciuresis, COPD (chronic obstructive pulmonary disease), post-traumatic brain injury, itching, sepsis or the like in mammalian, especially humans.
The present invention provides a pharmaceutical composition for the treatment of disease conditions mediated by bradykinin, in a mammalian subject, which comprises administering to said subject a therapeutically effective amount of a compound of formula (I).
Further, the present invention also provides a pharmaceutical composition for the treatment of inflammation, rheumatoid arthritis, cystitis, post-traumatic and post ischemic cerebral edema, liver cirrhosis, Alzheimer""s disease, cardiovascular disease, pain, common cold, allergies, asthma, pancreatitis, burns, virus infection, head injury, multiple trauma, rhinitis, hepatorenal failure, diabetes, metastasis, pancreatitis, neovascularization, corneal haze, glaucoma, ocular pain, ocular hypertension or the like, which comprises a therapeutically effective amount of the N-benzenesulfonyl L-proline compound of formula (I) or its pharmaceutically acceptable salt together with a pharmaceutically acceptable carrier.
Further, the present invention also provides a pharmaceutical composition for the treatment of Amyotrophic lateral sclerosis, Huntington""s disease, Parkinson""s disease, Multiple sclerosis, Stroke, head trauma, Post-surgical brain edema, Brain edema (general), Cytotoxic brain edema (such as that associated with brain tumors, stroke, head trauma, etc.), Brain edema associated with metabolic diseases (renal failure, pediatric metabolic diseases, etc.), Rheumatoid arthritis, Osteoarthritis, Migraine, Neuropathic Pain, Pruritis, Brain Tumor, Pseudotumor cerebri, Glaucoma, Hydrocephalus, Spinal cord trauma, Spinal cord edema, neurodegenerative diseases, respiratory diseases, diuresis, natriuresis calciuresis, COPD (chronic obstructive pulmonary disease), post-traumatic brain injury, itching or Sepsis, which comprises a therapeutically effective amount of a compound of formual (I) or its pharmaceutically acceptable carrier.
Also, the present invention provides a method for the treatment of disease conditions mediated by bradykinin, in a mammalian subject, which comprises administering to said subject a therapeutically effective amount of a compound of formula (I).
Further, the present invention provides a method for the treatment of inflammation, rheumatoid arthritis, cystitis, post-traumatic and post ischemic cerebral edema, liver cirrhosis, Alzheimer""s disease, cardiovascular disease, pain, common cold, allergies, asthma, pancreatitis, burns, virus infection, head injury, multiple trauma, rhinitis, hepatorenal failure, diabetes, metastasis, pancreatitis, neovascularization, corneal haze, glaucoma, ocular pain, ocular hypertension or the like, in a mammalian subject, which comprises administering to said subject a therapeutically effective amount of a compound of formula (I).
As used herein, the term xe2x80x9chaloxe2x80x9d is fluoro, chloro, bromo or iodo (preferably fluoro or chloro).
As used herein, the term xe2x80x9calkylxe2x80x9d means straight or branched chain saturated radicals, including, but not limited to methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, secondary-butyl, tertiary-butyl.
As used herein, the term xe2x80x9cC4-9 cycloalkylxe2x80x9d means monocyclic alkyl having 4 to 9 carbon atoms, such as cyclobutyl, cyclopentyl, cycloheptyl, cyclohexyl, and the like.
As used herein, the term xe2x80x9cC3-9 azacycloalkyl, C3-9 diazacycloalkyl, C5-11 azabicycloalkyl or C5-11 diazabicycloalkyl xe2x80x9d means a group wherein one or two carbons of mono- or bicyclic alkyl ring components are substituted by nitrogen atoms, included, but not limited to, azetidinyl, piperazinyl, piperidino, piperidinyl, pyrrolidinyl, azabicyclo[3.3.0]octyl, quinuclidinyl, azabicyclo[3.2.1]octyl, azabicyclo[3.3.1]nonyl, azabicyclo[2.2.2]octyl or diazabicyclo[3.2.1]octyl.
In the formula (I), R5 is preferably (a) xe2x80x94C3-9 diazacycloalkyl optionally substituted with C5-11 azabicycloalkyl or (c) xe2x80x94NHxe2x80x94C1-3 alkyl-C(O)xe2x80x94C5-11 diazabicycloalkyl, more preferably (a) xe2x80x94C4-8 diazacycloalkyl optionally substituted with C6-10 azabicycloalkyl or xe2x80x94NHxe2x80x94C1-3 alkyl-C(O)xe2x80x94C6-10 diazabicycloalkyl, further preferably azabicyclo[2.2.2]octyl-piperazinyl, diazabicyclo[3.2.1]octyl-oxomethylamino or diazabicyclo[3.2.1]octyl-oxoethylamino, and most preferably azabicyclo[2.2.2]octyl-piperazinyl or diazabicyclo[3.2.1]octyl-oxomethylamino.
Preferred compounds of this invention are those of the formula (I) wherein
X1 and X2 are chloro;
R1 and R2 are independently hydrogen, methyl or ethyl;
R3 and R4 are independently hydrogen or fluoro; and
R5 is
(a) xe2x80x94C4-8 diazacycloalkyl optionally substituted with C6-10 azabicycloalkyl;
(b) xe2x80x94C3-6 azacycloalkyl-NHxe2x80x94(C6-10 azabicycloalkyl optionally substituted with C1-4 alkyl);
(c) xe2x80x94NHxe2x80x94C1-3 alkyl-C(O)xe2x80x94C6-10 diazabicycloalkyl;
(d) xe2x80x94NHxe2x80x94C1-3 alkyl-C(O)xe2x80x94NHxe2x80x94C6-10 azabicycloalkyl, the C6-10 azabicycloalkyl being optionally substituted with C1-4 alkyl;
(e) xe2x80x94C4-8 azacycloalkyl optionally substituted with C4-8 azacycloalkyl; or
(f) xe2x80x94NHxe2x80x94C1-5 alkyl-NHxe2x80x94C(O)xe2x80x94C58 cycloalkyl-NH2.
Much preferred compounds of this invention are those of the formula (I) wherein
R1 and R2 are methyl; R3 and R4 are hydrogen; and
R5 is azabicyclo[2.2.2]octyl-piperazinyl, azabicylo[3.2.1]octanylaminoazetidinyl, diazabicyclo[3.2.1]octyl-oxomethylamino, diazabicyclo[3.2.1]octyl-oxoethylamino, methylazabicyclo[3.2.1]octyl-aminooxomethylamino, methylazabicyclo[3.2.1]octyl-aminooxoethylamino, ethylazabicyclo[3.2.1]octyl-aminooxomethylamino, piperidinopiperidinyl, [[(aminocyclohexyl)carbonyl]amino]propylamino or [[(aminocyclohexyl)carbonyl]amino]butylamino.
Also, preferred compounds of this invention are those of the formula (I) wherein
R5 is azabicyclo[2.2.2]octyl-piperazinyl, azabicylo[3.2.1]octanylaminoazetidinyl, diazabicyclo[3.2.1]octyl-oxomethylamino, methylazabicyclo[3.2.1]octyl-aminooxomethylamino, piperidinopiperidinyl or [[(aminocyclohexyl)carbonyl]amino]propylamino.
Preferred individual compounds of this invention are:
8-[[3-[[(2S)-2-[[4-[(3S)-1-Azabicyclo[2.2.2]oct-3-yl]-1-piperazinyl]carbonyl]pyrrolidinyl]sulfonyl]-2,6-dichlorobenzyl]oxy]-2,4-dimethylquinoline; and (2S)-N-[2-(3,8-Diazabicyclo[3.2.1]oct-3-yl)-2-oxoethyl]-1-[[2,4-dichloro-3-[[(2,4-dimethyl-8-quinolinyl)oxy]methyl]phenyl]sulfonyl]-2-pyrrolidinecarboxamide, and a salt thereof.
The N-benzenesulfonyl L-proline compounds of formula (I) of this invention may be prepared by a variety of synthetic methods. 
(wherein X1, X2, R1, R2, R3, R4 and R5 are as already defined; and WSC is 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride, HOBt is 1-hydroxybenzotriazole hydrate.
To a stirred solution of the acid of formula (II) (150 mg, 0.294 mmol) and amine H-R5 (0.441 mmol) in CH2Cl2 (15 mL) were added HOBt (67 mg, 0.441 mmol) and WSC (84 mg, 0.441 mmol) at room temperature and the mixture was stirred overnight. To the mixture was added H2O (5 mL) and the organic layer was separated, washed with saturated aqueous NaHCO3, brine, dried over MgSO4, filtered and concentrated in vacuo. Column chromatography (NH gel, 200-350 mesh, 8 g, CH2Cl2/MeOH=99/1 to 90/10) afforded the coupling product including a compound of formula (I).
In the described method A, 1,3-diisopropylcarbodiimide in place of WSC, t-BuOHxe2x80x94CH2Cl2(1-1), DMF, or AcOEt in place of CH2Cl2 were also used. For purification process, appropriate regins or solid-phase extraction method was also utilized when the small amount of the starting material (II) (about 50 Smol) were used.
To a stirred solution of the coupling product including a compound of formula (I) (0.0964 mmol) in MeOH was added HCl-MeOH (2.9 mL) and the mixture was stirred for 15 minutes. Then the solvent was removed in vacuo to provide the HCl salt.
Alternately, the N-benzenesulfonyl L-proline compounds of formula (Ia-II) were prepared by reaction of a compound (III) with a compound of formula (IV) as indicated in the following Scheme A-II. 
(wherein R is hydroxy, C1-4 alkoxy (such as methoxy and ethoxy) or R5; X3 is halo; and the other symbols are as already defined are as already defined)
This method utilizes a synthesis as described in WO97/07115. This reaction is carried out in a suitable reaction-inert solvent (anhydrous). Suitable solvents include, for example, aromatic hydrocarbons such as benzene, toluene and xylene; alcohols such as methanol, ethanol, propanol and butanol; ethers such as diethyl ether, dioxane and tetrahydrofuran; halogenated hydrocarbons such as methylene dichloride, chloroform, dichloromethane and dichloroethane; amides such as N,N-dimethylformamide; and nitrites such as acetonitrile. This reaction is carried out at a temperature between xe2x88x9210xc2x0 C. and 100xc2x0 C., preferably from 0xc2x0 C. to 50xc2x0 C. for 5 minutes to 24 hours, preferably 30 minutes to 5 hours.
In addition, the compounds (III) and (IV) which can be used herein may be either already known or may be prepared according to the reported methods.
The compounds of formula (III) was prepared by the reaction of a compound (V) with a compound of formula (VI) as indicated in the following Scheme B. 
(wherein X3 is halo; and the other symbols are as already defined)
This method utilizes a synthesis as described in WO97/07115. This reaction is carried out in the presence of base in a suitable reaction-inert solvent. Suitable base includes, for example, triethylamine. Suitable solvents include, for example, aromatic hydrocarbons such as benzene, toluene and xylene; alcohols such as methanol, ethanol, propanol and butanol; ethers such as diethyl ether, dioxane and tetrahydrofuran; halogenated hydrocarbons such as chloroform, dichloromethane and dichloroethane; amides such as N,N-dimethylformamide; and nitrites such as acetonitrile. This reaction is carried out at a temperature between xe2x88x9210xc2x0 C. and 100xc2x0 C., preferably from 0xc2x0 C. to 40xc2x0 C. for 5 minutes to 24 hours, preferably 30 minutes to 3 hours.
The compounds of formula (I), and the intermediates above-mentioned preparation methods can be isolated and purified by conventional procedures such as recrystallization or chromatographic purification.
The optically active compounds of this invention can be prepared by several methods known to a skilled person in the art. For example, the optically active compounds of this invention may be obtained by chromatographic separation or fractional crystallization from the final compounds or the intermediates in racemic form thereof. Alternatively, the optically active compounds may be prepared by optically selective reaction, enzymatic hydrolysis or reactions using optically active intermediates.
The N-benzenesulfonyl L-proline compounds of this invention possess an asymmetric center. Hence, the compounds can exist in separated (+)- and (xe2x88x92)-optically active forms, as well as in racemic one thereof. The present invention includes all such forms within its scope. Individual isomers can be obtained by known methods, such as optically selective reaction or chromatographic separation in the preparation of the final product or its intermediate.
The present invention includes salt forms of the compounds (I) as obtained above.
Insofar as the N-benzenesulfonyl L-proline compounds of this invention are basic compounds, they are capable of forming a wide variety of different salts with various inorganic and organic acids.
The acids which are used to prepare the pharmaceutically acceptable acid addition salts of the aforementioned N-benzenesulfonyl L-proline base compounds of this invention of formula (I) are those which form non-toxic acid addition salts, i.e., salts containing pharmaceutically acceptable anions, such as the chloride, bromide, iodide, nitrate, sulfate or bisulfate, phosphate or acid phosphate, acetate, lactate, citrate or acid citrate, tartrate or bi-tartrate, succinate, malate, fumarate, gluconate, saccharate, benzoate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate (i.e., 1.1xe2x80x2-methylene-bis-(2-hydroxy-3-naphthoate). The acid addition salts can be prepared by conventional procedures.
The N-benzenesulfonyl L-proline compounds of the present invention of formula (I) exhibit significant bradykinin receptor-binding activity and therefore, are of value in the treatment of a wide variety of clinical conditions in mammals, especially human. Such conditions include inflammation, cardiovascular disease, pain, common cold, allergies, asthma, pancreatitis, burns, virus infection, head injury, multiple trauma and the like.
Therefore, these compounds are readily adapted to therapeutic use as bradykinin antagonists for the control and/or treatment of any of the aforesaid clinical conditions in mammals, including humans.
Also, the compounds of formula (I) may be expected more effective therapeutic effects with being co-administered with H1-antagonist.
Further, the present invention also encompasses a pharmaceutical composition for the treatment of inflammation, rheumatoid arthritis, cystitis, post-traumatic and post ischemic cerebral edema, liver cirrhosis, Alzheimer""s disease, cardiovascular disease, pain, common cold, allergies, asthma, pancreatitis, burns, virus infection, head injury, multiple trauma, rhinitis, hepatorenal failure, diabetes, metastasis, cystitis, pancreatitis, amyotrophic lateral sclerosis, Huntington""s disease, Parkinson""s disease, multiple sclerosis, stroke, head trauma, post-surgical brain edema, brain edema (general), cytotoxic brain edema (such as that associated with brain tumors, stroke, head trauma, etc.), brain edema associated with metabolic diseases (renal failure, pediatric metabolic diseases, etc.), rheumatoid arthritis, osteoarthritis, migraine, neuropathic pain, pruritis, brain tumor, pseudotumor cerebri, glaucoma, hydrocephalus, spinal cord trauma, spinal cord edema, neurodegenerative diseases, respiratory diseases, diuresis, natriuresis calciuresis, COPD (chronic obstructive pulmonary disease), post-traumatic brain injury, itching, sepsis, or the like, which comprises a therapeutically effective amount of the N-benzenesulfonyl L-proline compound of formula (I) and H1-antagonist or their pharmaceutically acceptable salt together with a pharmaceutically acceptable carrier.
The compounds of the invention may advantageously be employed in combination with one or more other therapeutic ingredients selected from an antibiotic, anti-fungal, or anti-viral agent, an anti-histamine, a non-steroidal anti-inflammatory drug or disease modifying anti-rheumatic drug.
The combination with an anti-histamine (H1 antagonist) is particularly favorured for use in the prophylaxis and treatment of asthma and rhinitis. Examples of anti-histamine are chlorpheniramine, brompheniramine, clemastine, ketotifen, azatadine, loratadine, terfenadine, cetirizine, astemizole, tazifylline, levocabastine, diphenhydramine, temelastine, etolotifen, acrivastine, azelastine, ebastine, mequitazine, KA-398, FK-613, mizolastine, MDL-103896, levocetirizine, mometasone furoate, DF-1111301, KC-11404, carebastine, ramatroban, desloratadine, noberastine, selenotifen, alinastine, E-4716, efletirizine, tritoqualine, norastemizole, ZCR-2060, WY-49051, KAA-276, VUF-K-9015, tagorizine, KC-11425, epinastine, MDL-28163 terfenadine, HSR-609, acrivastine and BMY-25368.
The activity of the N-benzenesulfonyl L-proline compounds of the present invention, as bradykinin antagonists, is determined by their ability to inhibit the binding of bradykinin at its receptor sites in recombinant human bradykinin B2 receptor expressing CHO-KI cells (from Receptor Biology, Inc.) employing radioactive ligands.
The bradykinin antagonist activity of the N-benzenesulfonyl L-proline compounds is evaluated by using the standard assay procedure described in, for example, Baenziger N. L., Jong Y-J. I., Yocum S. A., Dalemar L. R., Wilhelm B., Vaurek R., Stewart J. M., Eur. J. Cell Biol., 1992, 58, 71-80. This method essentially involves determining the concentration of the individual compound required to reduce the amount of radiolabelled bradykinin ligands by 50% at their receptor sites in CHO-K1 cells, thereby affording characteristic IC50 values for each compound tested.
More specifically, the assay is carried out as follows. First, rat, guinea pig or monkey ileum tissues are minced and suspended in 25 mM piperazine-N,Nxe2x80x2-bis (2-ethanesulfonic acid (PIPES) buffer (pH 6.8) containing 0.1 mg/ml of soybean trypsin inhibitor. Then, the tissues are homogenized using a Polytron homogenizer at setting 7 for 30 seconds three times, and then rehomogenized with a Teflon-coated homogenizer. The homogenized suspension was centrifuged at 1,200xc3x97 g for 15 minutes. The pellet was rehomogenized and then centrifuged at 1,200xc3x97 g for 15 minutes. These supernatant were centrifuged at 10,000xc3x97 g for 60 minutes. The tissue pellets, CHO-K1 cell membrane are suspended in 25 mM PIPES buffer (pH6.8) containing 1.25 mM dithiothreitol, 1.75 xcexcg/ml bacitracin, 1 mM o-phenanthroline, 18.75 xcexcM captopril, 1.25 mg/ml bovine serum albumin (BSA), to prepare tissue/cell suspensions. Then, 10 xcexcl of test compound solution dissolved in phosphate buffered saline (PBS, pH 7.5) containing 2% DMSO (final) and 0.1% BSA (w/v) or 10 ml of 12.5 mM bradykinin in PBS (pH 7.5) containing 0.1% BSA (w/v) are placed in a reaction 96-well plate. 15 xcexcl of 8.3 nM [3H]bradykinin is added to the compound solution or bradykinin solution in the 96-well plate. Finally 100 xcexcl of the tissue or cell suspension are added to the mixture in the plate, and incubated at room temperature for 1 hour under the dark. After incubation, the resultant product in the reaction plates is filtered through 0.1% polyethylenimine presoaked LKB filermat. The filtrate is washed using a Skatron auto cell harvester. The tissue bound radioactivity is determined using a LKB betaplate counter. The IC50 value is determined using the equation:
Bound=Bmax/(1+[I]/IC50) 
wherein [I] means the concentration of the test compound.
All compounds prepared in the working examples as described below were tested by this method, and showed an IC50 value of 0.1 nM to 4 nM in CHO-KL cells with respect to inhibition of binding at its receptor.
The most preferred compounds prepared in the working examples as described below were tested by this method, and showed an IC50 value of 0.5 nM to 3.3 nM in CHO-K1 cells with respect to inhibition of binding at its receptor.
The possibility of drugxe2x80x94drug interaction of the N-benzenesulfonyl L-proline compounds of the present invention, as bradykinin antagonists, is determined by their ability to inhibit the testosterone 6xe2x96xa1-hydroxylase activity raised by CYP3A4 which is most abundant subtype of cytochrome P-450 in human.
This method essentially involves determining the concentration of the individual compound required to reduce the amount of 67-hydroxytestosterone by 50%.
More specifically, the assay is carried out as follows. Human liver microsomes (0.2 mg/ml) were mixed with appropriate concentrations of kinin B2 antagonist. Then, incubated with the presence of 50 xcexcM testosterone, 1.3 mM NADP+, 0.9 mM NADH, 3.3 mM glucose-6-phosphate, 3.3 mM MgCl2, and glucose-6-phosphate dehydrogenase (8 units/ml) in a total volume of 0.2 ml of 100 mM potassium phosphate buffer, pH 7.4, at 37xc2x0 C. After incubation (20 minutes), 10 xcexcl of methylalchol containing internal standard was withdrawn. The medium was filtrated by membrane filter with centrifugation at 1,800xc3x97 g for 10 minutes, and the resulting filtrate was taken.
xe2x96xa1xe2x96xa16xe2x96xa1-hydroxylated metabolite of testosterone in samples was analyzed by HPLC. A sample of 20 xcexcl was injected to the HPLC system equipped with a Polymer Cl 8 column (2.0xc3x9775 mm). The mobile phase consisted of 24% to 66% acetonitorile linear gradient including 10 mM ammonium phosphate, and with a flow rate of 0.35 ml/min.
The IC50 value is determined using the equation:
Activity=Activitycontol/(1+[I]/IC50) 
wherein [I] means the concentration of the test compound.
The most preferred compounds as memtined above of Working Examples showed IC50 values of more than 10 xcexcM.
T12 value against human liver microsome was calculated by conventional procedure. More specifically, human liver microsomes (0.2 mg/ml) were mixed with 1 xcexcM of kinin B2 antagonist and incubated with in the presence of 1.3 mM NADP+, 0.9 mM NADH, 3.3 mM glucose-6-phosphate, 3.3 mM MgCl2, and glucose-6-phosphate dehydrogenase (8 units/ml) in a total volume of 1.2 ml of 100 mM potassium phosphate buffer, pH 7.4, at 37xc2x0 C. At specified incubation times (0, 5, 10, 30 minutes), an aliquot of 100 xcexcl was withdrawn from the reaction mixture and mixed with 1 ml of acetonitrile containing internal standard. Protein was precipitated by centrifugation at 1,800xc3x97 g for 10 minutes, and the resulting supernatant was taken.
Bradikinin B2 antagonist in samples were analyzed by LS/MS/MS, in a Sciex API-300 mass spectrometer linked with a Hawlett-Pakkered HP1100 HPLC system. A sample of 20 xcexcl was injected to the HPLC system equipped with a Wakosil II 5C18 HG column (2.0xc3x97150 mm). The mobile phase consisted of 80% acetonitorile including 10 mM ammonium acetate, and the elution was isocratic with a flow rate of 0.3 ml/min. Part of the eluent from the HPLC column was introduced into the atmospheric ionization source via an ion spray interface. Txc2xd value is determined using the equation:
Txc2xd=0.693/k 
wherein k is elimination rate constant of the test compound.
The compounds of the formula (I) exhibit excellent biological activity in vitro and in vivo as bradykinin antagonists. Additionally, the compound of the formula (I) was stable against metabolism in human liver microsomes assay experiments. The most preferred compounds of Working Examples showed T112 values of more than 10 minutes.
The compound of this invention showed a good IC50 in CHO-K1 cells and a good Txc2xd value, which are essential for a practical drug.
The N-benzenesulfonyl L-proline compounds of formula (I) of this invention can be administered via either the oral, parenteral or topical routes to mammals. In general, these compounds are most desirably administered to humans in doses ranging from 0.3 mg to 750 mg per day, preferably from 10 mg to 500 mg per day, although variations will necessarily occur depending upon the weight and condition of the subject being treated, the disease state being treated and the particular route of administration chosen. However, for example, a dosage level that is in the range of from 0.06 mg to 2 mg per kg of body weight per day is most desirably employed for treatment of inflammation.
The compounds of the present invention may be administered alone or in combination with pharmaceutically acceptable carriers or diluents by either of the above routes previously indicated, and such administration can be carried out in single or multiple doses. More particularly, the novel therapeutic agents of the invention can be administered in a wide variety of different dosage forms, i.e., they may be combined with various pharmaceutically acceptable inert carriers in the form of tablets, capsules, lozenges, troches, hard candies, powders, sprays, creams, salves, suppositories, jellies, gels, pastes, lotions, ointments, aqueous suspensions, injectable solutions, elixirs, syrups, and the like. Such carriers include solid diluents or fillers, sterile aqueous media and various nontoxic organic solvents, etc. Moreover, oralpharmaceutical compositions can be suitably sweetened and/or flavored. In general, the therapeutically-effective compounds of this invention are present in such dosage forms at concentration levels ranging 5% to 70% by weight, preferably 10% to 50% by weight.
For oral administration, tablets containing various excipients such as microcrystalline cellulose, sodium citrate, calcium carbonate, dipotassium phosphate and glycine may be employed along with various disintegrants such as starch and preferably corn, potato or tapioca starch, alginic acid and certain complex silicates, together with granulation binders like polyvinylpyrrolidone, sucrose, gelatin and acacia. Additionally, lubricating agents such as magnesium stearate, sodium lauryl sulfate and talc are often very useful for tabletting purposes. Solid compositions of a similar type may also be employed as fillers in gelatin capsules; preferred materials in this connection also include lactose or milk sugar as well as high molecular weight polyethylene glycols. When aqueous suspensions and/or elixirs are desired for oral administration, the active ingredient may be combined with various sweetening or flavoring agents, coloring matter or dyes, and, if so desired, emulsifying and/or suspending agents as well, together with such diluents as water, ethanol, propylene glycol, glycerin and various like combinations thereof.
For parenteral administration, solutions of a compound of the present invention in either sesame or peanut oil or in aqueous propylene glycol may be employed. The aqueous solutions should be suitably buffered (preferably pH greater than 8) if necessary and the liquid diluent first rendered isotonic. These aqueous solutions are suitable for intravenous injection purposes. The oily solutions are suitable for intra-articular, intramuscular and subcutaneous injection purposes. The preparation of all these solutions under sterile conditions is readily accomplished by standard pharmaceutical techniques well known to those skilled in the art. Additionally, it is also possible to administer the compounds of the present invention topically when treating inflammatory conditions of the skin and this may preferably be done by way of creams, jellies, gels, pastes, ointments and the like, in accordance with standard pharmaceutical practice.